In the prior art, various devices have been proposed to determine squareness or perpendicularity of surfaces. In one type, a dial indicator is placed against a surface for which squareness is to be measured. U.S. Pat. No. 1,345,597 to Jantsch et al teaches a perpendicularity indicator using a dial indicator to measure the perpendicularity of an object. U.S. Pat. No. 5,133,135 to Durfee, Jr. discloses an angled gauge also utilizing a dial indicator to determine the squareness of surfaces on a work piece.
In the field of ice skate blades, U.S. Pat. No. 4,161,822 teaches a skate blade analyzer for determining the tangent or high point of the edge of the ice skate blade. Determination of the tangent enables a skate sharpener to change the location of the tangent point, if necessary, to improve the skater's performance.
In preparing ice skate blades for skating, it is important to make the ice skate blade edge square or perpendicular with respect to the blade side surface. When the blade edge of an ice skate is out of square, the skater must overcompensate through excessive leaning in one direction or the other. The degree of leaning is dependent on the amount the blade is out of square. This overcompensation and excessive leaning contributes to skate release and an increased incidence of falling due to the shift in body weight.
Prior art methods employ a crude visual test to determine skate blade squareness. For example, a coin such as a quarter is placed on the skate blade edge and a visual comparison is made with respect to the quarter and the blade side surface to judge squareness of the blade. However, these prior art methods are subject to error and inaccuracy and fail to give a consistent and accurate reading of the perpendicularity of the skate blade edge with respect to the skate blade side.
In view of the disadvantages of prior art methods, a need has developed to provide improved devices and methods for determining the squareness or perpendicularity of ice skate blade edges.